I think paintball and airsoft are about the same for range. (not 100%on that)
If you fill in your profile someone might be able to refer you to a place close to you to check out airsoft guns before you buy.
Also not sure of the age of your son but many fields are 18 plus only. There are exceptions made (especially if you are playing alongside him) but if he's only 13-14 it probably won't fly.
Also check out the FAQ's they have a TON of info that is intimidating but valuable to read.
Enjoy the true freedom that comes from being completely free of the shackles of reality.